Near field communication, abbreviated NFC, is a form of contactless communication between devices like smartphones or tablets. NFC encompasses a set of standards for such devices, which are often handheld or otherwise mobile, to establish radio communication with each other by touching them together or bringing them into close proximity, usually no more than a few centimeters. NFC peer-to-peer communication is possible provided both devices are powered. Communication is also possible between an NFC device and an unpowered NFC chip, often called a “passive tag” or simply “tag.”
NFC is a short-range, low-power communications protocol between two devices. An initiator device uses magnetic induction to create a radio-wave field that a target device can detect and access, allowing small amounts of data to be transferred wirelessly over a relatively short distance (e.g., less than 10 cm). More specifically, by using magnetic induction, the initiator device emits a small electric current, which creates a magnetic field that in turn bridges the physical space between the initiator device and the target device. The field is received by a similar coil in the target device, where it is turned back into electrical impulses to communicate data such as status information or any other information. So-called “passive” NFC tags use the energy from the initiator device to encode their response, while “active” or “peer-to-peer” tags have their own power source and respond to the initiator device using their own electromagnetic fields. Thus, NFC transmissions typically encompass two modes. In a passive communication mode, the initiator device provides a carrier field and the target device answers by modulating the existing field. In this mode, the target device may draw its operating power from the initiator-provided electromagnetic field, thus making the target device a transponder. In an active communication mode, both the initiator device and the target device communicate by alternately generating their own fields. A device deactivates its radio frequency (RF) field while it is waiting for data. In this mode, both devices typically have power supplies.
NFC devices may be able to receive and transmit data at the same time. Accordingly, the devices can check for potential collisions if the received signal frequency does not match with the transmitted signal's frequency.
NFC operates within the globally available and unlicensed radio frequency ISM band of 13.56 MHz. Most of the RF energy is concentrated in the allowed ±7 kHz bandwidth range, but the full spectral envelope may be as wide as 1.8 MHz when using ASK modulation. The working distance with compact standard antennas may extend up to 20 cm, but the practical working distance is smaller.
NFC transmissions are generally secure due to their short range and support for encryption. Applications will often use higher-layer cryptographic protocols (e.g., SSL) to establish a secure channel. Because loss of an NFC device may present a security issue, such devices are typically protected by additional security, such as an authentication code.
The NFC standards cover communications protocols and data exchange formats, which offer a secure connection with relatively simple setup, and can be used to bootstrap more capable wireless connections, such as Bluetooth and Wi-Fi connections.
Application of NFC transmissions and related communications to welding systems and methods are contemplated by the general inventive concepts, as shown and described herein.